Aiiah eebbock



Reiaued. July 21, 1926.

UNITED STATES PATENT OFFICE.

11A! nssocx, OI rous'r HILLS, m YORK.

raocass or name armor s'mnn.

' Io Drawing. Original In. 1,300,878, dated April 15, 1919, Serial No, 251,750, fledjamt $8, 1918. Ap-

plication for reissue fled June 4, 1926. Serial 10. 113,810.

The invention relates to a process of making alloy steel, and the object and advantages thereof will be set forth in part hereinafter, and in part will be obvious herefrom, or may be learnedby practice' with the invention. I a

The invention consists in the novel steps and processes herein described.

1 ticularly with molybdenum, the usual. ractice is to add or introduce into the used steel the molybdenumin the elemental form or in the form of a high grade alloy of molybdenum, usually with iron, known as 15 the ferro state, or ferro-molybdenum. This involves as a preliminary step, in order 'to obtain the molybdenum in the elemental or farm state, the reduction of the ores or salts of molybdenum to the metallic form, this bein usually don-a in an electric or other suitab e furnace. v

The oxides of molybdenum combine with the oxides of certain other elements, more especially with certain of the alkali metals;

and the alkaline-earth metals, of which calcium oxide may be regarded as an example,

to form a salt of the general type known as molybdate of calcium or other such element. ,In the case of these particular elements just enumerated these salts would be of the general form CaOMoO,.

At the present time, I prefer to employ the salts of calcium, molybdenum being the constituent element of the salt which reduces to rodu'ce the alloying metal for thesteel. ese salts of calcium can be I produced from the ores of molybdenum without the use of fumacing, and often these salts are necessari llyhproduced in the 40 ore-reduction recess. at is, the ferro state may be 0 ained or aProduced by furnace reduction of their c cium saltswhich have in turn been produced from the ores The present invention obviates the reliminary or Preparatory reduction of t e ores or salts o molybdenum to the metallic state, and rovides for introducing the alloying moly enum directly from the salt thereof into the steel.

'50 The procedure under my present method that instead of reducing the ores of mo ybdenum to the metallic state is essentiall in an outside furnace, and then introducing such alloying element into the molten stee u he calcium salt of molybdenum is added directly into the steel meltin furnace. The carbon content of the stee and its bath, which carbon is actually a previous alloy of the steel, reduces the calcium salt of the molybdenum, the so reduced molybdenum alloying directly with the steel. If desired other carbon may be added to, or substituted for, the carbon content of the steel audits In the manufacture. of steel, alloyed par-' bath. The calcium oxide which is a constituent of the salt fixes the molybdenum andrprevents its volatilization, thus avoiding loss, and presents the mo] bdenum capable of alloying directly with the steel in the melting furnace. Some suitable reducing agent other than carbon, such as silicon, which also niay be a revious alloy of the steel, may be employe in the melting furnace. There are thereby eliminated the outside reduction of the ores or salts of molybdenum, with the attendant time, cost and labor, and large furnace losses of this costly element are likewise avoided.

What I claim is 2- 1. The process of-making alloy steel which comprises reducing calcium molybdate at furnace temperature in the presence of fused steel by means of carbon as a reducing agent whereby the reduced molybdenum is caused to enter the steel.

2. The process of making alloysteel which comprises reducing calcium molybdate at furnace temperature in the presence of fused steel where y the reduced molybdenum is caused to enter the steel as an alloy.

3. The process of making molybdenum alloy steel which comprises reducing a salt 'of molybdenum by introducing the salt directly into the steel melting furnace during the steel making process and reducin the salt by. the action of a constituent o the.

molten steel in the furnace, whereby the molybdenum is reduced directly from its salt and immediately enters the steel.

4. The process of making alloy steel which comprises reducing a. calcium salt of molybdenum by subjecting the salt to furnace temperature in the presence of fused steel by the carbon or silicon content of the steel and its bath employed in the steel process acting directly upon the salt whereby'the molybdenum is reduced from the salt and directly enters the steel as an alloy.

In testimony whereof, I have signed my name to this specification. t

ALAN KISSOCK. 

